It is known for industrial trucks to use an electric or hydraulic steering drive in combination with a so-called electric steering mechanism. The steering angle predetermined by the steering wheel or similar operating member is transmitted electrically to a steering drive which is disposed in the direct vicinity of the driven or steered wheel. The steered wheel is rotatably supported about a horizontal axis in a bearing component and the bearing component, in turn, is pivotally supported about a vertical axis. If the steered wheel is also a driven wheel the bearing component is defined by the casing of a transmission which is in an operatively connection to a driving engine. Both the driving engine and transmission are frequently arranged in a body bolster which is pivotable about a vertical axis.
It is well imaginable to transmit the steering torque to the bearing component by means of a linear motor. However, a rotary piston engine is provided in most cases which acts upon the bearing component via a gear transmission. The transmission of the torque to a ring gear of the bearing component, for example, from the pinion of the rotary piston engine is performed either by means of a chain or even directly. Undesirable noise will be emitted specifically in case of a direct transmission to the ring gear from the pinion of the driving motor because two mechanically rigid systems engage each other.
It is the object of the invention to provide a steering drive for an industrial truck which reduces the development of noise although there is a direct engagement of a pinion with a ring gear.